Swallowing assessment in obstructive sleep apnea: insights from surface electromyography

Area of Science:

• Neurology
• Physiology
• Sleep Medicine

Background:

• Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with various health complications.
• Dysphagia and altered muscle activity during swallowing are potential consequences of OSA.
• The suprahyoid/submental (SH) muscles play a crucial role in the oral phase of swallowing.

Purpose of the Study:

• To investigate electromyographic (sEMG) activity of SH muscles during swallowing in adults with varying OSA severities.
• To control for body mass index (BMI) in the analysis of SH muscle activity.
• To identify predictive factors influencing SH muscle activation changes in OSA patients.

Main Methods:

• A cross-sectional observational study included 37 adults diagnosed with OSA, categorized into mild-to-moderate (AHI 5–30) and severe (AHI > 30) groups.
• Surface electromyography (sEMG) recorded SH muscle activity during voluntary swallowing of thin liquid.
• Statistical analyses included multivariate analysis of covariance (ANCOVA) with BMI as a covariate and general multivariate linear regression (GRM).

Main Results:

• Patients with severe OSA (Group II) exhibited significantly lower sEMG peak, Vmax, and integral values compared to those with mild-to-moderate OSA (Group I).
• The apnea-hypopnea index (AHI) and BMI were significant predictors for SH muscle peak and integral values.
• Tongue volume and swallowing behavior were identified as key predictors for the maximum velocity (Vmax) of SH muscle activation.

Conclusions:

• Severe OSA is associated with reduced activation of the suprahyoid (SH) muscles during swallowing.
• Both OSA severity, BMI, and tongue myofunctional status contribute to impaired SH muscle activation.
• These findings suggest that muscle weakness and motor control deficits compromise SH muscle function in OSA patients, potentially impacting swallowing safety.